The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engine systems include an engine that combusts an air/fuel mixture within cylinders to generate drive torque. Air is drawn into the engine through an intake and is then distributed to the cylinders. The air is mixed with fuel and the air/fuel mixture is combusted. A fuel system typically includes a fuel rail that provides fuel to individual fuel injectors associated with the cylinders. One or more of the fuel injectors may be utilized to deliver fuel to the engine during a given time period.
A period of time that the fuel injectors are energized is referred to as a pulse-width (PW). Typically, the pulse-width for each of the fuel injectors is determined based on a determined quantity (e.g., mass) of fuel, size of the fuel injectors (i.e. fuel flow capacity), and pressure of the fuel supplied.
Direct injected (DI) engines supply fuel directly to an engine's cylinders. DI engines generally tend to operate at a higher pressure than other types of engines, such as port fuel injected (PFI) engines.
Over time, fuel injector coking can occur. Fuel injector coking refers to the accumulation of deposits on an orifice of a fuel injector. Fuel injector coking often occurs in a non-uniform fashion across the fuel injectors. As a result of coking, discharge coefficients of fuel injectors and the corresponding flow of fuel out of the injectors may be adversely affected. This may reduce fuel efficiency.